What does the cryptic crossword clue "Instrument for Rick Wakeman Roger Dean transformed? (9)" mean?

The definition is "Instrument". The wordplay uses an anagram. anagram of ROGER + DEAN = REEDORGAN; definition: "Instrument" The answer is REEDORGAN.

Instrument for Rick Wakeman Roger Dean transformed? (9)

Independent Cryptic #1792 | 15 Across | 2024-06-30 flower